From 1eba49357bb42c6e17dd521c1bb439987869d0a1 Mon Sep 17 00:00:00 2001
From: Niklas Dewally <niklas@dewally.com>
Date: Tue, 25 Jun 2024 21:24:10 +0100
Subject: [PATCH] fix: broken nightly builds

In recent versions of the nightly / beta compilers, the use of linkme
causes linker errors. (dtolnay/linkme#94) This
is due to the new linker set as default in these versions.

Add linker flags to nightly builds to revert to the old linker
behaviour.

See:

- dtolnay/linkme#88
- https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html

Signed-off-by: Niklas Dewally <niklas@dewally.com>
---
 .github/workflows/code-coverage-main.yml |  4 ++++
 .github/workflows/code-coverage.yml      |  4 ++++
 .github/workflows/test.yml               |  6 +++++-
 readme.md                                | 14 ++++++++++++++
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/code-coverage-main.yml b/.github/workflows/code-coverage-main.yml
index 8060378fb1..50da0d7dd1 100644
--- a/.github/workflows/code-coverage-main.yml
+++ b/.github/workflows/code-coverage-main.yml
@@ -27,6 +27,10 @@ jobs:
       - name: Install rust ${{ env.rust_release }}
         run: rustup update ${{ env.rust_release }} && rustup default ${{ env.rust_release }}
       
+      - name: Disable rust-lld (to fix linkme)
+        run: echo RUSTFLAGS=${RUSTFLAGS}\ -Zlinker-features=-lld >> $GITHUB_ENV
+        if: matrix.rust_release == 'nightly'
+
       - uses: ./.github/actions/install-conjure
         with: 
           os_arch: linux
diff --git a/.github/workflows/code-coverage.yml b/.github/workflows/code-coverage.yml
index d983307f0b..686960b92a 100644
--- a/.github/workflows/code-coverage.yml
+++ b/.github/workflows/code-coverage.yml
@@ -40,6 +40,10 @@ jobs:
 
       - name: Install rust ${{ env.rust_release }}
         run: rustup update ${{ env.rust_release }} && rustup default ${{ env.rust_release }}
+
+      - name: Disable rust-lld (to fix linkme)
+        run: echo RUSTFLAGS=${RUSTFLAGS}\ -Zlinker-features=-lld >> $GITHUB_ENV
+        if: matrix.rust_release == 'nightly'
       
       - uses: ./.github/actions/install-conjure
         with: 
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d59d163835..ec99c9ca77 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -24,7 +24,7 @@ on:
 env:
   SCCACHE_GHA_ENABLED: "true"
   RUSTC_WRAPPER: "sccache"
-  SCCACHE_GHA_VERSION: 2
+  SCCACHE_GHA_VERSION: 4
 
 jobs:
   build-and-test:
@@ -54,6 +54,10 @@ jobs:
       - name: Run sccache-cache
         uses: mozilla-actions/sccache-action@v0.0.3
 
+      - name: Disable rust-lld (to fix linkme)
+        run: echo RUSTFLAGS=${RUSTFLAGS}\ -Zlinker-features=-lld >> $GITHUB_ENV
+        if: matrix.rust_release == 'nightly'
+
       - run: rustup update ${{ matrix.rust_release }} && rustup default ${{ matrix.rust_release }}
 
       - run: cargo build -vv --workspace
diff --git a/readme.md b/readme.md
index dc829b0e75..70daa85d71 100644
--- a/readme.md
+++ b/readme.md
@@ -13,6 +13,20 @@ This repository hosts the following projects:
 This project is being produced by staff and students of University of St
 Andrews, and is licenced under the [MPL 2.0](./LICENCE).
 
+## Rust Nightly Support
+
+The following compiler flags are required for Conjure-Oxide to work with
+Nightly Rust:
+
+```sh
+export RUSTFLAGS="-Zlinker-features=-lld" 
+cargo build <...>
+```
+
+This is because of current incompatibilities with linkme and the new default
+linker ([link](https://github.com/dtolnay/linkme/issues/94)).
+
+
 ## Documentation
 
 API documentation can be found [here](https://conjure-cp.github.io/conjure-oxide/docs/).